Dental composite resin direct fillings have become preferred to amalgam fillings as a material to replace tooth structure lost from cavities and accidents. In addition, tooth-colored composite resin can be used to effect cosmetic improvement to the shape and color of natural teeth. The conventional dental composite resins exist in a variety of chemical formulas, with different fillers, shades, viscosities, and properties. Different types of composite resins can be described as unfilled resins and bonding agents, sealants, flowable composites, and restorative composites.
The unfilled resin and bonding agents are generally relatively colorless and used in adhesive systems to bond composite resin to teeth. Sealants are unfilled or lightly filled and may be colorless, or whitish. The flowable composites are used to fill small cavities, to seal teeth, and as a liner for larger fillings. The restorative composites are used fill larger recesses, and they range from a buttery consistency to a fairly dense putty-like material.
As composite resin technology has improved, and as the cosmetic expectation of patients to have natural-looking dental work has increased, techniques have been developed to layer composite resin material, using slightly different natural tooth-colored shades and opacities of material to achieve a strong and aesthetic result.
Unfortunately, the skills necessary to master the placement of two or more natural tooth-colored shades of composite resin are not the same skills necessary to condense and overfill amalgam into a cavity preparation. Dentists must learn to manage slightly different shades and opacities of composite resin material in three dimensions to achieve an optimally natural-looking tooth in shape and color.
When dentists, who were trained to overfill a cavity with amalgam filling material, are faced with a need to place the correct amount and color of material in each layer without overfilling, only those with strong three-dimensional perception and an excellent sense of color are able to adjust and create an aesthetically acceptable result. Two-dimensional illustrations typically used for training are not easily translated to three dimensions and do not provide the dentist, technician, student, hygienist, or other trainee an opportunity for hands-on practice. Training with existing products involves the use of conventional composite resin materials having shade differences so subtle that the different layers of composite resin materials are usually too difficult for the trainee to adequately perceive in an educational setting. In addition, the subtle shade differences cannot be discriminated in photographs. Accordingly, a system is needed that can simplify the visualization process and provide direct and immediate feedback to the trainee and to the instructor.